Chronograph mechanism

ABSTRACT

Chronograph mechanism including first ( 20, 22 ) and second ( 21, 23 ) measured time counters and control means ( 24 ) arranged so as to start to stop one or other of the counters and a switching device ( 25 ) arranged such that the actuation thereof causes the started counter to stop and the stopped counter to start.

The present invention relates to chronograph mechanisms, which allowmeasurement of a time counted from a given instant, controlled by anapplication of pressure on push-buttons.

A watch provided with such a mechanism is, for example, disclosed in thework entitled “Théorie d'horlogerie”, Chs-A. Reymondin et al. ISBN2-940025-10-X, page 232 and following. These watches generally includetwo push-buttons, one for assuring the starting and stopping of thecounter measuring the measured time, the other for setting the counterto zero. This time is displayed by means of at least one hand, generallyarranged at the centre of the movement and indicating the time inseconds.

These watches enable the duration of an event, which may or may not haveinterruptions, to be timed. For certain applications, for example formeasuring the thinking time of chess players, it is necessary to use anad hoc apparatus or to use two chronographs.

It is an object of the present invention to propose a chronographmechanism for measuring the duration of two events occurring in analternating process. This mechanism is intended to cooperate with amovement including:

-   -   a frame for carrying the components of the movement,    -   means for counting the current time, including an energy source,        a time base and a going train.

It includes more particularly:

-   -   means for counting measured times,    -   coupling means, arranged for engaging and releasing the measured        time counting means from the current time counting means, and    -   means for actuating the coupling means.

According to the invention this mechanism is characterized in that:

-   -   the means for counting measured times include first and second        chronograph gear trains, each intended to carry a hand, which        respectively assure the display of a first and a second measured        time,    -   the coupling means include first and second coupling clutches,        for coupling the going train respectively to the first and the        second chronograph gear trains,    -   the actuating means include:        -   a control device arranged so as to engage or release one            coupling clutch or the other, and        -   a switching device arranged such that actuation thereof            causes the engaged coupling clutch to be released and the            released coupling clutch to be engaged.

In order to allow counting from zero, the actuation means furtherinclude an initialisation device, arranged for controlling the zeroresetting of the measured time counting means.

In order to prevent the proper working of the mechanism being disturbedor ruined by manipulations, its switching device includes a lockingstructure arranged such that it can only be actuated when one of thechronograph gear trains is coupled.

Moreover, the locking means cooperate with the actuation means, suchthat the initialisation means cannot be actuated when one of thechronograph gear trains is coupled.

Other advantages and features of the invention will appear from thefollowing description, made with reference to the annexed drawing, inwhich:

FIG. 1 shows a watch including a mechanism according to the invention,

FIG. 2 shows an operating diagram of said watch, and

FIGS. 3 to 6 show the mechanism according to the invention, in differentpositions, corresponding to the main steps encountered during operation.

In the following description, the position of the various components ofthe watch is, sometimes, defined with reference to the position occupiedby an hour hand on the dial.

FIG. 1 shows a watch 10, including a case 12, a dial 14, a winding andtime-setting crown 16, five hands bearing the references 18 to 23 andthree push-buttons, bearing the references 24 to 26.

In a conventional manner, case 12 contains and protects a movementincluding a mechanism allowing time to be measured, as will be explainedhereinafter. It is closed by a glass, not visible in the drawing, whichcovers dial 14 and hands 18 to 23. Hands 18 and 19 pivot at the centreof dial 14. They display respectively the hours and minutes of thecurrent time. Hands 20 and 21 are arranged concentrically to hands 18and 19. They are respectively driven by a first and a second counter andare for displaying the seconds of a first and a second measured time.Hands 22 and 23, which are off-centre and associated with a smallunreferenced dial placed at three o'clock, display the minutesrespectively of the first and second measured times. Hands 20 to 23 arethus means for displaying measured times.

Push-button 24, placed at two o'clock, controls either the start, or thestopping of the measurement of one or other of the two measured times,in accordance with a logic that will be described with reference to FIG.2. Push-button 25, coaxial to crown 16, switches from counter toanother, and push-button 26 resets hands 20 to 23 to zero. In order toproperly understand the operating principle of the mechanism accordingto the invention, FIG. 2 shows schematically the effect caused by anapplication of pressure onto one push-button or the other.

In this diagram, the push-buttons that are inactive in the variousstates that the mechanism can take have not been taken intoconsideration. Generally, it appears that push-button 24 can be actuatedwhatever the state of the mechanism. Push-button 25 is only active ifone of the counters or the other is in operation, whereas push-button 26can only carry out a zero reset when the first counter is stopped andthe second counter is stopped or at zero.

In this Figure, the rectangles in bold print relate to actions P1, P2and P3 carried out by the user of the watch respectively on push-buttons24, 25 and 26.

The rectangles in thin lines indicate the changes brought about by theaction concerned on the mechanism. In these rectangles, C1 and C2identify respectively the first and second counters, Start, Stop andReset, their start, stop and reset. The circles surrounding a capitalletter define the various states in which the mechanism is found afterthe action, listed in the table hereinafter. State First counter Secondcounter A At zero At zero B Counting At zero C Stopped At zero D StoppedCounting E Stopped Stopped F Counting Stopped

The watch is in state A when there is no time being measured, hands 20,21, 22 and 23 being at zero. In this state, only one application ofpressure P1 on push-button 24 is acting. It causes the first counter tostart and hands 20 and 22 to start to move, hands 21 and 23 remaining atzero, which corresponds to state B of the mechanism. In this state,another application of pressure on push-button 24 (P1) has the effect ofstopping the first counter, and consequently hands 20 and 22 indicatingthe measured time, which corresponds to state C of the mechanism. Anapplication of pressure on push-button 25 (P2) is also possible. Itcauses the counters to switch, i.e. the first to stop and the second tostart, the mechanism then being in state D.

When the mechanism is in state C, another application of pressure onpush-button 24 (P1) causes the first counter to start again, bringingthe mechanism to state B, whereas an application of pressure onpush-button 26 (P3) causes hands 20 and 22 to be reset to zero and areturn to state A.

When the mechanism is in state D, an application of pressure onpush-button 24 (P1) causes the second counter to stop, the first alsobeing stopped, which corresponds to state E. Still in state D, anapplication of pressure on push-button 25 (P2) causes the counters toswitch again, the first counter restarting, whereas the second counterstops. The mechanism is then in state F.

If the mechanism is in state E, an application of pressure onpush-button 24 (P1) causes the second counter to start again, whichcorresponds to state D, whereas an application of pressure onpush-button 26 (P3) resets the two counters to zero, the mechanism thenreturning to its initial state A.

When the mechanism is in state F, push-buttons 24 (P1) and 25 (P2) canbe actuated, which is comparable to state B. In state F however, thesecond stopped counter, indicates a measured time, whereas in state B,it was at zero.

The mechanism assuring these functions is shown in FIGS. 3 to 6. It isarranged on a plate forming a frame 28, part of the base movement andable, for example, to further assure a barrel bridge function. It is onthe back cover side of the watch. In FIG. 3, its constituent parts arein state A as defined with reference to FIG. 2, i.e. in the state inwhich the mechanism is at rest, hands 20 to 22 being at zero. FIG. 4corresponds to state B, FIG. 5 to state D, and FIG. 6 to state C or D.

In these Figures several parts are superposed. Depending upon whetherthe part is visible or masked, the line linking the part to itsreference numeral includes or does not include a point at the endthereof attached to the part.

Moreover, numerous springs assure the positioning and return of themobile parts. In order to avoid overloading the drawing, they have beenrepresented by an arrow Fi (i being the reference of the part on whichit acts), indicating the direction of force that they generate. The tipof the arrows is applied in proximity to the point of contact. When twoidentical parts are superposed, the reference of the spring includes anoblique bar followed by the last figure of the reference of the lowerpart.

In these Figures, push-buttons 24 to 26 are represented schematically bytheir end, which is arranged inside the case.

The base movement has not been shown. It includes, in a conventionalmanner, an energy source, a time base, and a going train connecting theenergy source to the time base and consequently counting the currenttime. This train includes a wheel set provided with an arbour passingthrough frame 28 and carrying two wheels 301 and 302, whose functionwill be specified hereinafter.

Frame 28 includes:

-   -   means for counting measured times 40,    -   coupling means 50,    -   actuating means 60, and    -   initialisation means 70, the latter only being visible, in        detail, in FIG. 6.

The measured time counting means 40 include two wheels 421 and 422, ofthe same diameter and provided with the same number of teeth, disposedcoaxially to the centre of the movement, and arranged respectively forcarrying hands 20 and 21. They also include two coaxial wheels, whichhave not been shown in the drawing, arranged for pivoting on frame 28 ina hole 28 a, and respectively driven by wheels 421 and 422, at the rateof one step per minute or half-minute, and arranged such that hands 22and 23, which they respectively carry, complete one revolution in thirtyminutes. These wheels of measured time counting means 40 are eachprovided with a heart-piece, not shown in the drawing, for cooperatingwith the initialisation means in order to set the hands to zero.

Coupling means 50 include two levers 521 and 522, mounted so as to pivoton frame 28, in their median part on the same axis, which is outside thescope of the drawing. These levers 521 and 522 carry, at one of theirends, a freely mounted wheel identified by the letter a. They areprovided, at the other end, with a nose identified by the letter b forcooperating with actuating means 60, as will be explained hereinafter.Wheels 521 a and 521 b are disposed such that they are permanentlymeshed respectively with wheels 301 and 302 and sequentially with wheels421 and 422, with reference to the actuating means, as will be specifiedhereinafter.

In this arrangement, wheel 421 and the first of the wheels pivoting at28 a that are not shown together form the first measured time geartrain, whereas wheel 422 and the second of the wheels that are not shownform the second measured time gear train. Lever 521, with its wheel 521a, form the first coupling clutch and lever 522, with its wheel 522 a,forms the second.

Actuating means 60 are controlled by push-buttons 24, 25 and 26. Theyinclude:

-   -   a start and stop control lever 61 provided with:        -   a body 61 a pivoting, in its median part, on frame 28 at 28            c,        -   a control pin 61 b arranged on body 61 a at one of its ends,        -   a drive click 61 c, mounted so as to pivot on body 61 a at            the other end and positioned by a pin 61 d secured to body            61 a,        -   a push-button pin 61 e, arranged facing push-button 24, and        -   a release pin 61 f;    -   superposed coupling-releasing levers 621 and 622, each including        a body identified by the letter a and pivoting in its median        part at the same point 28 d of frame 28, and each provided with        a click identified by the letter b, for controlling the starting        and stopping respectively of the first and second counter, a        release cut out portion identified by the letter c and a finger        identified by the letter d and extending in proximity to        push-button 25;    -   a switching lever 64, including:        -   a body 64 a mounted so as to pivot, in its median part, on            the frame at 28 e,        -   an arm 64 b, articulated on body 64 a and carrying a pin 64            c arranged for cooperating with push-button 25 and fingers            621 d and 622 d,        -   a click 64 d, mounted so as to pivot at the free end of arm            64 b, positioned by a pin 64 e, also secured to arm 64 b,        -   a contact finger 64 f, disposed on body 64 a between its            pivoting point 28 e and its end carrying arm 64 b, and        -   a release pin 64 g arranged on body 64 a, at the opposite            end to that carrying arm 64 b;    -   a selection lever 65, formed of:        -   a body 65 a mounted so as to pivot, via its median part, at            28 f on frame 28, and provided at one of its ends with a            nose 65 b,        -   an arm 65 c articulated on the other end of body 65 a and            provided at its free end with an activation pin 65 d;    -   two coaxial column wheels 661 and 662, mounted so as to pivot on        the frame at 28 g, which each include a ratchet wheel        cooperating respectively with clicks 621 b and 622 b, and a set        of columns respectively cooperating with noses 521 b and 522 b        (the structure of these wheels has not been shown in detail,        since it is well known to those skilled in the art);    -   two coordination wheels 67 and 68, pivoting respectively at 28 h        and 28 j, and each including a star-wheel with 6 teeth        identified by the letter a and a cam b including three bosses c        separated by hollows d, arranged regularly over the periphery of        cam b; and    -   an inter-cam lever 69 including a body 69 a mounted so as to        pivot in its median part at 28 k on frame 28 and including a        finger 69 b abutting against cam 67 b, an index 69 c for        cooperating with pin 61 f, the finger and the index being in        proximity to wheel 67, whereas the other end, close to wheel 68,        includes, mounted so as to pivot, a click 69 d and a pin 69 e,        secured to body 69 a and acting as a stop for click 69 d.

Initialisation means 70 are all visible only in FIG. 6. They include acontrol lever 71 and a hammer 72, respectively mounted so as to pivot at281 and 28 m on frame 28.

Lever 71 carries a pin 71 a, arranged such that push-button 26 canactuate it. It is provided with a nose 71 b, required to cooperate withclick 69 d, and an arm 71 c, forming a stop for hammer 72.

Hammer 72 is formed of a body 72 a, which carries, in proximity to itspivoting point 28 m, a pin 72 b and two superposed noses 721 c and 722c. Pin 72 b is for cooperating with arm 71 c, whereas noses 721 c and722 c are arranged for respectively working with the columns of wheels661 and 662.

The other end of body 72 a carries two arms 72 d and 72 e each providedat its free end with two superposed heels, namely heels 721 d and 722 dfor arms 72 d, 721 e and 722 e for arm 72 e. These heels are forcooperating with the heart-pieces with which the wheels carrying hands20 to 23 are provided.

In the mechanism thus described, the rest position of the various partsof which it is made is, generally, defined by the action of a springholding each part against a stop. As was explained hereinbefore, thesesprings are represented simply by an arrow, in order to avoidoverloading the drawing.

Thus, as long as no pressure is exerted on push-button 24, lever 61 isheld in the position shown in FIG. 3 via the action of a spring F61 a,schematically represented by an arrow, as explained hereinbefore,abutting against a stop that has not been shown in the drawing. A springF61 c holds click 61 c abutting against pin 61 d.

Bodies 62 la and 622 a of levers 621 and 622 are respectively held inplace, against a stop that is not shown, by superposed springs F621 aand F622 a designated F621/2 a in FIG. 3. Clicks 621 b and 622 b arerespectively biased by springs tending to keep them in contact with theratchet of column wheels 661 and 662, designated F621/2 b.

Switching lever 64 abuts via its contact finger 64 f against cam 67 b,via the effect of a spring F64 a acting on its body 64 a. Arm 64 b ispressed against a stop secured to frame 28 and schematically representedby a pin 28 n, via the effect of a spring F64 b. Click 64 d ispositioned against pin 64 e by a spring F64 d.

Selection lever 65 is biased by a spring F65 a, acting on body 65 a suchthat nose 65 b abuts against cam 68 b, and a spring F65 c applying arm65 c via pin 65 d against lever 621 or 622.

In order to hold inter-cam lever 69 abutting via its finger 69 b againstcam 67 c, its body 69 a is biased by a spring F69 a. The position ofclick 69 d, abutting against pin 69 e, is assured by a spring F69 d.

Lever 71 is controlled by a spring F71, which tends to resist the forceapplied by push-button 26.

A spring F72 a is pressed against the body 72 a such that the heels abutagainst the heart-pieces when neither the noses nor pin 72 a are heldany longer respectively by arm 71 c and the columns of wheels 661 and662 (FIG. 6).

Column wheels 661 and 662 and coordination wheels 67 and 68 arepositioned by jumper springs that are not shown in the drawing.

It should be noted that the actuating means described hereinbeforefulfil both a control and switching function. Thus they form a controldevice, essentially formed by lever 61 and levers 621 and 622, and aswitching device essentially formed of switching lever 64 and selectionlever 65.

When the device is in state A, as shown in FIG. 3, and pressure isexerted on push-button 24, the latter moves to abut against push-buttonpin 61 e, which causes control lever 61 to pivot. In this movement, pin61 b enters into contact with arm 65 c, which is also driven, such thatits pin 65 d is applied against lever 621, which pivots at 28 d.However, lever 622 remains stationary, since its cut out portion 622 cis opposite pin 65 d.

Click 621 b drives column wheel 661 such that nose 521 b is locatedbetween two columns and lever 521 moves until wheel 521 a meshes withwheel 421. Thus, the first measured time counter is started.Simultaneously, click 61 c, cooperating with star-wheel 67 a drivescoordination wheel 67.

Switching and inter-cam levers 64 and 69, abutting against cam 67 b,also tip to take to position shown in FIG. 4. The tipping of lever 64brings pin 64 c into the space swept by push-button 25, thus fulfillingthe function of a coupling clutch structure allowing the switchingdevice to be actuated, as will be explained hereinafter. These movementsof the levers do not have an immediate effect, all they do is to placethe parts such that they can be actuated subsequently, as will beexplained hereinafter.

Although only shown in FIG. 6, hammer 72 also pivots when push-button 24is actuated. Indeed, because of the rotation of column wheel 661, nose721 c is raised by a column. Heels 721 d, 722 d, 721 e and 722 e thenrelease the wheels of the chronograph gear trains, particularly wheels421 and 422.

It will be noted that, in state A, any action on push-button 25 will nothave any effect, since there are no parts cooperating therewith. Anapplication of pressure on push-button 26, however, causes lever 71 topivot. In this state, hammer 72 is in the initialisation position, i.e.abutting against the heart-pieces comprised in wheels of the chronographgear train. As will be explained hereinafter, this movement of lever 71thus has no effect.

Since the mechanism has passed from state A to state B, shown in FIG. 4,it is then possible to actuate push-buttons 24 or 25. Any action onpush-button 26, however, has no effect. Hammer 72 is removed from thewheels, and lever 71 is moved away from pin 72 b, but hammer 72 remainsstationary, its nose 722 c abutting against a column of column wheel662.

In a similar manner to that described hereinbefore with reference toFIG. 3, actuating push-button 24, in state B, causes lever 61 to move,which causes column wheel 661 and coordination wheel 67 to move throughone step. The rotation of column wheel 661 brings nose 521 b to abutagainst a column, such that wheel 521 a is, again, uncoupled from wheel421.

The mechanism is then in state C, i.e. the first counter is stopped anddisplay the first measured time, whereas the second counter is at zero.In this state, the mechanism occupies the same position as that shown inFIG. 3. There are however two differences between states A and C. On theone hand, the counter for the first measured time is no longer at zero,and on the other hand, hammer 72 is in the wheel release position andnot in the initialisation position. These differences do not appear inFIG. 3.

If the user presses push-button 25, the latter will abut against pin 64c, which causes arm 64 b of switching lever 64 to pivot on its body 64a.

Pin 64 c simultaneously pushes levers 621 and 622, abutting againsttheir fingers 621 d and 622 d, such that clicks 621 c and 622 crespectively drive column wheels 661 and 662 through one step. Lever521, which was between two columns, moves to abut against one column,whereas lever 522, which was abutting against a column, falls betweentwo columns. Consequently, wheel 521 a is uncoupled from wheel 421,which interrupts the counting of the first measured time, and wheel 522a is coupled with wheel 422, which starts the counting of the secondmeasured time.

With the movement of arm 64 b, click 64 d pushes coordination wheel 68through one step. Since selection lever 65 is abutting against it, viaits nose 65 b, it tips and takes a position such that pin 65 d isopposite cut out portion 621 c.

The mechanism has thus passed to state D, which is shown in FIG. 5. Inthis state, any action on push-button 26 has no effect, but this time,it is column wheel 662 which prevents hammer 72 from tipping.

In state D, it is also possible to actuate push-buttons 24 and 25. In asimilar manner to that explained hereinbefore, an application ofpressure on push-button 24 causes lever 61 to pivot, which drives arm 65c, which is in a position such that its pin 65 d controls only lever622. The latter rotates column wheel 622 through one step, such thatlever 522 a abuts against a column and wheel 522 a and is uncoupled fromwheel 422. The second counter, like the first, is thus stopped, whichtherefore corresponds to state E, in which the parts shown in thedrawing occupy the same position as in state C. The only difference liesin the position of hand 21, which displays a time, whereas in state C itis at zero.

When the mechanism is in state D, which is shown in FIG. 5, anapplication of pressure on push-button 25 again actuates arm 64 b, andwith it the two levers 621 and 622, such that the first counter, whichhad stopped, starts again, whereas the second counter stops, whichcorresponds to state F. In other words, as soon as one counter rotates,an application of pressure on push-button 25 causes it to stop and theother to start.

The controls for the mechanism, when it is in state E, are the same aswhen it is in state C, and in state B when it is in state F. Thesesituations will not therefore be described in more detail.

When the mechanism is in state C or E, it is possible to reinitialisethe counters, as can be seen in FIG. 6, by an application of pressure onpush-button 26, which abuts against pin 71 a of lever 71. This causeslever 71 to pivot, such that arm 71 c no longer holds pin 72 b. Sincethe two noses 721 c and 722 c are located between two columns of wheels661 and 662, hammer 72 falls under the force of spring F72, heels 721 d,721 e, 722 d and 722 e then drive the cams carried by the wheel sets ofthe chronograph gear trains, to reinitialise them.

Moreover, nose 71 b pushes click 69 d, which drives coordination wheel68 via its star wheel 68 a such that selection lever 65 occupies theposition where an application of pressure on push-button 24 causes thefirst measured time counter to start.

It is clear that the mechanism as it has just been described, is only anexample embodiment. It is also possible to achieve the same object withvariants relying on other components, or the same ones, but havingdifferent forms, without thereby departing from the scope of theinvention.

It should be noted that the solution described requires less energy thanchronograph mechanisms with fly-back hands, while enabling more complexand accurate measurement.

1. Chronograph mechanism for cooperating with a movement including: aframe for carrying the components of the movement, means for countingthe current time, including an energy source, a time base and a goingtrain, said mechanism including: means for counting measured times,coupling means, arranged for engaging and releasing the measured timecounting means from the current time counting means, and means foractuating the coupling means characterized in that: said means forcounting measured times include first and second chronograph geartrains, each intended to carry a hand, which respectively assure thedisplay of a first and a second measured time, said coupling meansinclude first and second coupling clutches, for connecting the goingtrain respectively to the first and the second chronograph gear trains,said actuating means include: a control device arranged so as to engageor release one coupling clutch or the other, and a switching devicearranged such that actuation thereof causes the engaged coupling clutchto be released and the released coupling clutch to be engaged. 2.Mechanism according to claim 1, characterized in that said actuatingmeans further include an initialization device arranged for controllingthe resetting to zero of the measured time counting means.
 3. Mechanismaccording to claim 2, characterized in that the switching deviceincludes a coupling structure arranged such that it can only be actuatedwhen one of the chronograph gear trains is coupled.
 4. Mechanismaccording to claim 1, characterized in that the actuating means includea locking structure arranged such that the initialisation device cannotbe actuated when one of the chronograph gear trains is coupled. 5.Mechanism according to claim 2, characterized in that the actuatingmeans include a locking structure arranged such that the initialisationdevice cannot be actuated when one of the chronograph gear trains iscoupled.
 6. Mechanism according to claim 3, characterized in that theactuating means include a locking structure arranged such that theinitialisation device cannot be actuated when one of the chronographgear trains is coupled.